Self-latching fastening mechanism



March 23, 1965 M. J. MARIN SELF-LATCHING FASTENING MECHANISM Filed July 2, 1962 INVENTOR. MAR/0 MA R/N ATTOR/Vf) Z a H x V: w w 2/ M $1 a m States Patent 3,174,785 SELF-LATC G FASTENING MECHANISM Mario J. Marin, Bethe], Conn., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed July 2, 1962, Ser. No. 206,934 3 Claims. (Cl. 292-228) This invention relates, generally, to latching devices for fastening either hinged or removable panel-like members to a supporting frame work, the invention relating more particularly to fastening mechanism of this character which is self-latching when the member which it fastens is moved into proper latching position and which is manually releasable quickly and with minimum effort.

The invention is herein disclosed in an embodiment adapted for fastening casework panels to the frame of a business machine. When employed for such purposes, it is desired that the latch mechanism be substantially concealed so as not to detract from the appearance of the equipment in which it is employed; that it be readily accessible and quickly operable to minimize the time required for opening or removing the panel member; and further, that it be adaptable for restricted access or for release by a special tool so as to prevent operation by other than properly authorized persons. The device according to the present invention serves all these purposes since it is disposed entirely on the interior side of the panel member with access thereto being provided by a hole or opening in the panel member, and if it is desired to restrict operation of the latch to only authorized persons, such as service or maintenance personnel, the access opening can readily be made in a suitable or appropriate configuration adapted to receive a similarly configured tool made available only to the selected personnel for this purpose.

An operating portion of the mechanism is designed to lie flush with the interior surface of the panel member and completely cover the access opening in the panel member, thereby minimizing surface irregularities in the panel member and contributing to a pleasing, unbroken appearance of the panel. One advantageous feature of the device resides in the design of the catch member of the mechanism which readily lends itself to adjustment relative to the manually operable latching arm to thereby facilitate assembly of the related equipment and to enable the parts to be easily adjusted in precise alignment.

It is therefore an object of the invention to provide an improved latching device for fastening panel-like members to a supporting framework.

It is the further object of the invention to provide a latching device of the character described which is disposed entirely on the interior surface of the object to be latched and is easily accessible for manual release.

It is the further object of the invention to provide a self-locking, manually releasable latching device which is of simplified design, comprised of a minimum number of parts and is easily adjusted to maintain its associated parts in precise alignment.

Further objects of the invention together with the features contributing thereto and the advantages accruing therefrom will be apparent from the following description when read in conjunction with the drawing wherein:

FIG. 1 is an exploded perspective view of the mechanism separate from the casework on which it would be mounted.

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FIG. 2 is a side elevation of the device attached to casework and shown with the parts in latching position.

FIG. 3 is a view similar to FIG. 2 but with the parts shown in the releasing position.

FIG. 4 is a front view of the mechanism.

FIG. 5 is a front view of a modification of the mechanism as adapted for operating with a plurality of catch means.

Referring now to FIG. 1, the device will be seen to include a latch lever 10 which may be formed of bar metal stock and is double-reversely bent to provide a flat limit arm 11, a bent over shank 12, and a reversely bent latching arm 13, the edge of which is preferably rounded off for reasons which will hereinafter be apparent. At the bend between shank 12 and arm 13, the lever is drilled to provide a pivot bearing for receiving a pivot pin 15.

The lever 10 is pivotally secured, by means of the pivot pin, to a bracket member 20 which may be stamped out of a single blank of sheet metal and is formed to provide spaced apart bent ears 21 and a connecting rib 22. Holes 23 punched in the ears 21 are adapted to receive the ends of the pivot pin 15 to thereby provide a pivotal support for the lever It).

A leaf spring 25 shaped with turned under ends is secured at one end by any suitable means, such as screws or the like, to the rib 22 of the bracket 20, the opposite end of the spring thus being adapted to bear against the rear surface of the limit arm 11 of the latch lever thereby biasing the lever in a clockwise direction.

The rounded off edge of the latch arm 13 is adapted to engage with a catch mechanism 30 which comprises a circular disc 31 mounted eccentrically on a threaded stud 32, the periphery of the disc being formed with a notch defining angularly opposed surfaces 33, 34, the surface 33 not being visible in FIG. 1. A backup nut 35 provides means whereby the stud may be secured to the frame of the casework, and locking nuts 36 provide means whereby the disc 31 may be retained in an adjusted position on the stud 32.

Referring now to FIGS. 2 and 3, the device is shown installed on machine casework comprising a vertically disposed panel 49 and a box like frame rib 41, the panel is this instance being pivotally mounted on the casework frame by means of a pivot bearing 42 attached to the underside of the panel and riding in a trough formed by an angular bearing bracket 43 secured to the casework frame. The stud 32, with the disc 31 firmly secured thereto, is suitably fastened to the rib 41 by means of the backup nut 35. The latch lever bracket 20 is suitably secured to the inside surface of the panel 41 such as, for example, by welding the bracket ears 21 to the panel. When the bracket 20 is fastened to the panel, the limit arm 11 of the latch lever 10, due to the configuration of the latch lever, lies flush against the inner surface of the panel 40 and is retained in this position yieldably by the leaf spring 25.

The relative positioning of the latch lever 10 and the catch mechanism 30 is such that when the panel is in its fully closed position, such as shown in FIG. 2, the rounded edge of the latch arm 13 will be in bearing contact with the groove surface 33 of the disc 31, and the side surface of the arm 13 will butt against the groove surface 34. It will be apparent that any force tending to swing the panel outwardly to an open position will} exert a clockwise thrust on the latch lever which, however, will be blocked from clockwise rotation due to the interference of the disc surface 34 with the latch arm 3 13 and the panel 40 itself with the limit arm 11 of the latch lever. Thus, the panel is effectively locked in the latched position shown in FIG. 2.

Release of the latching mechanism is achieved by manual depression of the limit portion 11 of the latch lever inwardly against tension of the spring 25 to rotate the latch lever counterclockwise to the point where the rounded-off edge of the latch arm 13 is below and clear of disc 31. It will be noted that the geometry of the parts is such that the surface 33 of the catch disc 31 lies in a plane which is substantially tangential to the arc defined by the rotation of the latch arm 13 at the point where the arm is in latching position, i.e. that of FIG. 2. Therefore, it will be apparent that the latch lever 10 is freely rotatable in a counterclockwise direction against the tension of the spring 25. In order to provide access for manual release of the latch lever, an access opening 45, see FIG. 4, is formed in the panel 40 in register with the limit arm 11 of the latch lever, said opening being of sufiicient size to enable the finger of an operator to project therethrough for the purpose of rotating the latch lever. The opening 45 also provides means enabling the panel to be gripped for separating same from the caseworl; frame. If it were desired to partially restrict access to the mechanism, a smaller opening could be provided so as to require use of a small instrument, such as a pencil or the like, for releasing the device. In instances where it might be desired that a panel be removed only by authorized persons, the access opening may be made in a special configuration, not shown, which would not permit insertion of a finger, or a pencil like member, and only authorized personnel would be provided with a correspondingly configured tool which could be inserted in such an opening for the purpose of rotating the latch lever to the release position.

Upon insertion or restoring the panel to the closed position, it will be apparent that the mechanism selflatches under the influence of the spring 25 after the latch arm 13 wipes across the rim of the disc 31.

in casework of the type herein described, it is customary to equip the removable panels around their inner edge with a seal made of yieldable or compressible material, such as the gasket 48, for the purpose of providing a snug fit, reducing vibration, etc. In a panel so equipped, the elasticity within the gasket serves to press the latch arm 13 against the grooved surfaces of the catch disc 31 so as to thereby assure a snug and tight fit of the parts.

An important feature of the instant invention resides in the mounting of the disc 31 which, as heretofore mentioned, is eceentrically supported by the stud 32, best seen in FIGS. 25, and enables an easy and accurate adjustment to be made vertically in the disposition of the disc 31 in assembling the device on related casework. The adjustment is achieved by loosening the locking nuts 36 and rotating the disc 31 to the point where the grooved surfaces 33, 34 are in correct vertical disposition relative to the latch arm 13, and then tightening the locking nuts to hold the disc in the adjusted position. Through this feature, the need for maintaining precise tolerance in locating the mounting holes for the support stud 32, and in positioning the latch lever bracket 2t? on the panel is avoided. Of course, any lateral adjustment of the disc 30 can also be easily achieved simply by taking up on the backup nut 35 to thereby axially adjust the disposition of the threaded stud 32.

FIG. illustrates a modified version of the device wherein a plurality of catch members 30 are provided and are arranged so as to be simultaneously engageable by a single latch lever which thereby holds the panel latched at a corresponding plurality of points. In this embodiment of the device the structural features are similar to those heretofore described with the exception that the width of the latch lever is extended to provide a correspondingly elongated latch arm 51 and limit arm 52. This modified latch lever is pivotally supported at each end by individual pivot brackets 53 in association with individual leaf springs 54, the limit arm of the lever being cut away to allow suitable clearance from the modified form of pivot bracket utilized in this embodiment.

Although the device has been shown in forms adapted for machine casework having a pivotal panel, it will of course be apparent that the device is equally well adapted to panels which are completely removable and not provided with a pivotal mounting. t will also be apparent that the device is equally well adaptable for effecting the latching closure of members other than panels of machine casework.

While there has been shown and described what are regarded as preferred embodiments of the device, it will of course be understood that changes in form could be made without departing from the spirit of the invention, and it is therefore intended that the invention be not limited to the exact forms herein shown and described nor to anything less than the whole of the invention as hereinbefore set forth and as hereinafter claimed.

What is claimed and desired to be secured by Letters Patent is:

1. A fastening device for securing removable enclosures or the like to a supporting frame comprising: a latch lever pivotally mounted on the interior surface of said enclosure, said lever being formed on one side of its pivotal axis with a latch arm arranged to frictionally engage a catch member and on the other side of its pivotal axis with a limit arm adapted to be yieldably biased into engagement with the interior surface of said enclo sure, said enclosure being formed with an access opening in register with said limit arm; a spring member having one end mounted on said enclosure and its other end bearing on said lever to urge said limit arm into engagement with the surface of said enclosure and said latch arm into engagement with a catch member; a circular catch member adapted to be mounted upon said frame, said catch member being formed with a peripheral groove to receive and retain the edge of said latch arm when said enclosure is in the closed position relative to said frame; a mounting member arranged to be mounted on one end upon the frame and at a second end to receive said catch member; and means to eccentrically mount said catch member upon said mounting member, to permit rotative adjustment of said catch member to accurately position said peripheral groove in relation to said latch arm.

2. A fastening device for securing removable enclosures or the like to a supporting frame comprising: a latch lever pivotally mounted on the interior surface of said enclosure, said lever being formed on one side of its pivotal axis with a latch arm arranged to frictionally engage a catch member and on the other side of its pivotal axis with a limit arm adapted to be yieldably biased into engagement with the interior surface of said enclosure, said enclosure being formed with an access open- 1ng in register with said limit arm; a spring member having one end mounted on said enclosure and its other end bearing on said lever-to urge said limit arm into engagement with the surface of said enclosure and said latch arm into engagement with a catch member; a circular catch member adapted to be mounted upon said frame, said catch member being formed with a peripheral groove, a first surface of said groove disposed tangential to the rotatable arc defined by said latch arm, to receive and retain the edge of said latch arm when said enclosure i in the closed position relative to said frame; a threaded stud mounting member arranged to be mounted on one end upon the frame and at a second end to receive said catch member; said stud being arranged for relative movement with respect to said frame; to permit correct location of said catch member with respect to said frame; and means to eccentrically mount said catch member upon said stud, to permit rotative adjustment of said catch member to accurately position said peripheral groove in relation to said latch arm.

3. A fastening device for securing removable enclosures or the like to a supporting frame comprising: a latch lever pivotally mounted on the interior surface of said enclosure, said lever being formed on one side of its pivotal axis with a latch arm having a rounded latching surface at its extreme end arranged to frictionally engage a catch member and on the other side of its pivotal axis with a flat surfaced limit arm adapted to be yieldably biased on a first surface into engagement on a second surface with the interior surface of said enclosure, said enclosure being formed with an access opening in register with said second surface of said limit arm, whereby said latch lever may be pivoted about said axis by applying a force to said second surface of said limit arm; a flat spring member having one end mounted on said enclosure and its other end bearing on said first surface of said lever to urge said second surface of said limit arm into engagement with the surface of said enclosure and said rounded latching surface into engagement with a catch member; a circular catch member adapted to be mounted upon said frame, said catch member being 2 formed with a peripheral groove, a first surface of said groove disposed tangential to the rotatable arc defined by said latch arm, to receive and retain the rounded latching surface of said latch arm when said enclosure is in the closed position relative to said frame; a threaded stud mounting member arranged to be mounted on one end upon the frame and at a second end to receive said catch member; said stud being arranged for relative movement with respect to said frame, to permit correct location of said catch member with respect to said frame; and means to eccentrically mount said catch member upon said stud, to permit rotative adjustment of said catch member to accurately position said peripheral groove in relation to said latch arm rounded latching surface.

References Cited by the Examiner UNITED STATES PATENTS 473,888 4/92 Saxton 292340 X 1,675,155 6/28 Bremer 292-34119 2,197,195 4/ 4t) Schemers 292228 X FOREIGN PATENTS 11,514 1913 Great Britain.

M. HENSON WOOD, JR, Primary Examiner. 

1. A FASTENING DEVICE FOR SECURING REMOVABLE ENCLOSURES OR THE LIKE TO A SUPPORTING FRAME COMPRISING: A LATCH LEVER PIVOTALLY MOUNTED ON THE INTERIOR SURFACE OF SAID ENCLOSURE, SAID LEVER BEING FORMED ON ONE SIDE OF ITS PIVOTAL AXIS WITH A LATCH ARM ARRANGED TO FRICTIONALLY ENGAGE A CATCH MEMBER AND ON THE OTHER SIDE OF ITS PIVOTAL AXIS WITH A LIMIT ARM ADAPTED TO BE YIELDABLY BIASED INTO ENGAGEMENT WITH THE INTERIOR SURFACE OF SAID ENCLOSURE, SAID ENCLOSURE BEING FORMED WITH AN ACCESS OPENING IN REGISTER WITH SAID LIMIT ARM; A SPRING MEMBER HAVING ONE END MOUNTED ON SAID ENCLOSURE AND ITS OTHER END BEARING ON SAID LEVER TO URGE SAID LIMIT ARM INTO ENGAGEMENT WITH THE SURFACE OF SAID ENCLOSURE AND SAID LATCH 